WO2004070501A2

WO2004070501A2 - System for tracking an article

Info

Publication number: WO2004070501A2
Application number: PCT/GB2004/000440
Authority: WO
Inventors: Karlis Obrams; Christopher Reginald Chatwin; Rupert Charles David Young; Frederic Vladimir Claret-Tournier; David Robert Worrall; Sian Lowri Worrall; Roger James Mortimer
Original assignee: Xvista Limited
Priority date: 2003-02-07
Filing date: 2004-02-05
Publication date: 2004-08-19
Also published as: EP1595223A2; GB0302791D0; WO2004070501A3

Abstract

A system for tracking an article, such as for determining authenticity thereof, includes a unique random code (8) on or associated with the article (6). The code can be detected and compared with information relating to the article corresponding to the code stored in a remote database (12). Data is transmitted between the detector (4) and the database to determine whether the article is authentic.

Description

SYSTEM FOR TRACKING AN ARTICLE

This invention relates to a system for tracking an article, such as for determining authenticity thereof. The invention is particularly applicable to the tracking of articles from manufacture to a point of sale and is particularly intended to reduce losses resulting from sale of counterfeit or unauthorised goods.

Counterfeiting of goods is a major global problem and results in revenue losses in many different countries. Counterfeit fraud represents a large market for the criminal community and is a fraud without frontiers. In Europe alone- this crime costs the community some 50 billion pounds and an estimated 3 to 4 percent of world turnover is lost to counterfeit crime. This is besides loss of revenue for manufacturers, who, having developed brands or products, are harmed by sub-standard, and in some cases dangerous, products being passed off as genuine branded products. Manufacturers, customers and governments are affected by such actions.

Methods exist for marking of articles of goods and for retrospective identification and authentication. For example US-A-5 380 047 describes the tagging of an article with a unique code number attached by means of a tamper-proof adhesive. A list of code numbers and the articles to which they relate is maintained and can be interrogated to verify the authenticity of the article.

O-A-0062238 describes a unique mark, which contains a product control code that is printed in invisible ink comprising a UV ink and an IR ink. US-A-β 309 690 describes a system whereby a unique identifier is provided in the form of a spatial orientation of micro-coded marks .

A problem, which is not solved by the prior art, is to provide a system which is able to track an article and verify its authenticity at every stage of its life cycle from manufacture to point of sale, including verification that the article is not only genuine, but is in a specified location. This is particularly important in connection with customs and excise operations, where goods destined for particular world markets should only be present in specifically designated locations .

It is an object of the present invention to overcome or minimise this problem.

According to the present invention there is provided a system for tracking an article, such as for determining authenticity thereof, the system comprising:

a unique random code means on or associated with the article;

means adapted to detect the unique random code means;

a remote database adapted to store information relating to the article corresponding to the unique random code means; and

means adapted to transmit data between the detecting means and the database.

The database may be a secure database. Means, which may be secure, may be provided for updating the database in event of change of status of the at least one article being tracked.

The transmitting means may be adapted for two-way transmission between the detecting means and the database .

The code means may be, for example, in the form of a unique random one or two dimensional bar code or a pattern representing a unique random number. Alternatively, the code means may be in the form of a maxi-code, a unique pattern, a data matrix, a snowflake, a radio frequency identification tag, or may be numeric or alphanumeric. The code means in itself contains no information about the article to which it is applied. Data regarding the article may be acquired from the database following secure database access with appropriate authentication. If desired, the code means may be encrypted.

The system may include global positioning system (GPS) means for determining the location of the article each time the code means is detected by the detecting means, location data relating to the article corresponding to the code means being stored in the database. In this way, the location of the article may be determined or verified each time the code means is detected.

The means for transmitting the data between the means for detecting the code means and the database may comprise wire or wireless means. Such wireless means may comprise radio waves, infrared, Bluetooth or 802.11 (Wi-Fi) technology. The means for detecting the code means may be adapted to communicate with a server means, which is adapted to communicate by way of a secure link with a central server means which securely holds the database.

When wireless means is provided, the means for detecting the code means may be directly linked with a portable computer, which may be adapted to analyse the transmitted data and which may be linked by a fixed connection, such as wire means, or by wireless means, to the database.

When a fixed connection is used, connection may be by way of the Internet or a custom communication system (for example a modem telephone link) and a radio transmitter may be added to the means for detecting the code means .

The code means attached to the article by printing or weaving it onto a securely attached label which forms part of the article, is particularly applicable to the labelling of textiles. Direct printing of the code means onto the article is particularly applicable for labelling of articles such as DVDs. The code means may be applied to a wide range of different materials, for example fabrics, paper, plastics, metals, glass, or wood.

The articles may be individually labelled and may be sealed as batches in containers, with each batch having its own unique code means arranged to update the location of the articles as and when they move as a batch. As soon as one of the articles from within the batch is scanned, the code means for the batch will become invalid, resulting in a need to separately scan the individual articles. The articles and /or batches can be scanned on entry to and exit from a location, such as a storage area or warehouse or retail outlet, such that the whereabouts of an article can be always known right through to a point of sale. The precise geographical location of the articles can be verified in real time by way of Global Positioning System (GPS) technology. This system may also be used to prevent the return of stolen goods for refunds, as the records in the database will reveal that the particular article had never been sold.

The code means may be covert. For example, a luminescent code means may be applied to a non-luminescent background. Alternatively, a non-luminescent code means may be applied to a luminescent background.

A fiducial mark may be provided to indicate the location of the code means on the article. Alternatively, the code means may be applied at any desired location on the article and such that its location is only known to an authorised person.

The detecting means may comprise means for activating the covert code means to enable interrogation thereof, and means for interrogating the activated code means.

The covert code means may be invisible to the naked eye and may be adapted to be activated by response to application of an external stimulus by the activating means. Thus, where the background is luminescent, the activation means may activate the background to luminesce and to reveal the code means by virtue of the contrast between the non-luminescent code means and the luminescent background. The detecting means may be operated at any suitable wavelength from infra-red through to ultra-violet, there being some advantage in reading the covert code means at wavelengths invisible to the human eye . The external stimulus may comprise an optical or thermal stimulus, or an electrical stimulus such as an applied electric field or electric current. Alternatively, the covert code means may, by virtue of its intrinsic properties, elicit a response in the detecting means. Intrinsic properties may include optical, electrical or dielectric properties of the covert code means.

The means for detecting the covert code means may be selected from optical, electrical, photo-electrical, capacitative and electro-optical means, and combinations thereof .

The covert code means may be applied to the article by weaving, dyeing or printing means. Such printing means may comprise screen printing, inkjet printing, offset printing, or letterpress, or a combination thereof. The covert code means may be applied directly to the article, or to one or more labels applied to the article.

The covert code means may be selected from a photo- responsive material, a thermo-responsive material, an electro-responsive material, and a material with specific optical, dielectric or conductivity properties, and a combination of two or more such materials.

The photo-responsive material may be selected from a photo-chromic material and a photo-luminescent material. Such photo-chromic material may comprise a material selected from bianthrones, fulgides, spiropyrans, spirooxazines, pyrans, oxazines, naphthopyrans, spironaphthoxazines, diarylethenes, and mixtures thereof.

Where employed, activation of the photo-chromic material may be by means of an ultra-violet light source and detection may be by means of an optical detection device, such as a charge coupled device (CCD) camera, or a bar code reader, operated in association with appropriate analysing software.

The photo-chromic material may be selected from photo- reversible and thermally reversible materials . When the photo-chromic material is photo-reversible, the colour thereof may be removed using a second application of light. In this case, when the photo-chromic material is a fulgide, it may be initially activated by exposure to ultra-violet light and then deactivated by exposure to visible light.

When the photo-chromic material is a thermally reversible material, such as a spiropyran, a rate of fade of colour thereof after activation may be monitored as a security check, such rate of fade being determined by temperature, presence of stabiliser material and also nature of any matrix within which the material is contained. A temperature sensor may be provided to compensate for any temperature dependence of the rate of decolouration.

The photo-luminescent material may comprise luminescent molecules selected from anthracenes, fluoresceins, rhodamines, coumarins and indocyanine green. The emission of such molecules may range from ultraviolet, through blue and red, to a near infrared region of the spectrum. Activation of the photo-luminescent material may be effected by means of a filtered light source, such that the luminescent molecule in the material absorbs at a wavelength of irradiation of the filtered light from the source. Detection may be effected by measuring a subsequently-emitted image by means such as a charge coupled device (CCD) camera, in association with analysing software.

The thermo-responsive material may comprise a thermo- chromic material which may be activated to produce a change in colour thereof by application of heat. Such heat may be applied directly, or indirectly such as by passing an electric current through a substrate on which the photo-chromic material is deposited, such that the substrate is caused to heat up. The change in colour may be interrogated in association with analysing software.

The thermo-chromic material used for the covert code means may be selected from a copper or silver salt of mercuric iodide, such as Cu₂HgI₄ or Ag₂HgI₄, doped or undoped vanadium dioxide, 2, 5-dinitrosalicylic acid (DNSA) , and a liquid crystalline material.

The electro-responsive material may be selected from an electro-luminescent material, an electro-chromic material and an electrically conducting polymer material. The electro-responsive material may itself respond to an external stimulus by changing, for example, its emissive, absorptive or conductive properties, or may by virtue of its intrinsic properties, such as dielectric properties, elicit a response in the detecting means.

The electro-luminescent material may be selected from a derivative of poly (p-phenylene vinylene) , polythiophene or a polymer doped with a luminescent molecule.

The electro-luminescent material may be sandwiched between an anode and a cathode means. At least one of the anode and cathode may be any suitable optically transparent thin conducting film, for example a vapour- deposited or sputtered semiconductor, such as tin-doped indium oxide, fluoride-doped tin oxide, or a metal such as platinum or gold, supported on a transparent glass or polymer substrate. Where appropriate, the electro- luminescent material may be activated by application of a voltage, such that an image is produced which is detected by means such as a charge coupled device (CCD) camera, together with associated analysing software.

The electro-chromic material may be selected from viologens, metal hexacyanoferrates, metallopolymers, metallocyanines and polymers which change colour on application of an electrical potential. The electro- chromic material may be chemically or electrochemically deposited onto either or both of an anode and a cathode.

The electro-chromic material (s) may be provided as patterned layer (s) deposited on either or both of an anode and a cathode means and activated by application of a voltage and such that a resulting coloured image may be detected by means such as a charge coupled device (CCD) camera, in association with analysing software. An ion- conducting electrolyte with negligible electronic conductivity may separate the anode and cathode means and provide ionic charge transport. The ion-conducting electrolyte may be solid, liquid or polymeric. The anode and cathode means may be arranged to both form part of a label on the article. Alternatively, either the anode or the cathode means, together with the electro-chromic material and ion-conducting electrolyte, may be applied as a label to the article, with a corresponding cathode or anode means provided separately as part of the interrogating means . The electrically conducting polymer material may be selected from poly (pyrrole) , poly (aniline) , poly (thiophene) , poly (acetylene) , poly (isothionaphthene) and poly (p-phenylene) . Such electrically conducting polymer material has an intrinsic dielectric property and may be activated by application of an electric field thereto and detected by capacitive sensing means such as a capacitive array detector. Alternatively, the presence of the covert code means may be detected by a capacitive detecting means by virtue of its intrinsic dielectric properties .

The covert code means may be disguised beneath or within an existing label, such as a bar code, data matrix or proprietary brand, on the article, in such a way that the presence of one coding means does not interfere with reading out of the other.

The covert code means may be created by changing an existing code. For example, in the case of an existing bar code or data matrix, additional lines may be added, or line widths reduced or enlarged, such as to alter the number and/or nature of alphanumerics encoded within the bar code or data matrix.

Where an existing code is changed, the covert code means may be applied as either an electro-responsive material or a photo-responsive material, or a substrate to which the covert code means is applied may be responsive. In the case of an electro-responsive material, the covert code means may be applied as the electro-responsive material or may be applied as an electrolyte, such that a response is only elicited where there is contact between the electrolyte and the electro-responsive material. Where an increase in security level is required for an article, the spectral and/or temporal characteristics of the covert code means, or one or more components thereof, as detected by the detecting means may be employed as an additional security device. The spectral and/or temporal characteristics, either intrinsic or in response to a stimulus from the detecting means, of the covert code means, or one or more components thereof, may be recorded by the detecting means together with the unique code and may be compared with the database to provide further authentication.

Alternatively or additionally, where an increase in security level is required for an article a combination of materials may be employed for the covert code means.

For example, a conducting polymer material may be applied in conjunction with a photo-chromic material and such that only successful detection, by the detecting means, of both materials, when activated, will result in verification of the article. In a further way of increasing the security level in respect of the article, the covert code means may comprise two differently- coloured photo-chromic materials, such as on a label, each requiring different detection wavelengths and deactivating at different rates. Where different wavelengths and/or deactivation rates are used as security devices, spectral and/or temporal data are detected by the detecting means and compared with those held in the database together with the unique code.

The covert code means in its active form is arranged to have a sufficient contrast ratio (background to foreground) to allow satisfactory detection. The code means may be detected using a custom-built reader which, where appropriate, is equipped with a suitable activating source for the covert code means, such as a source of ultra-violet illumination, a magnetic or electric field generator, or a voltage source and associated electrodes. Activation of the covert code means reveals a code, which may be invisible to the naked eye. In the case of a photo-chromic material used for the code means, synchronisation is achieved between the ultra-violet illumination and a laser or light-emitting diode (LED) required to read the code. Detection of the unique code means can be achieved optically, electro- optically or capacitively, using an optical detection device, such as a camera, operable in any part of the electromagnetic wave spectrum, a bar code reader, a capacitive array, or any other suitable device. For optical detection, the covert code means can be detected under ambient lighting or using illumination provided in association with the detecting means. The covert code means may be scanned and then translated or converted using a bar code reader, character recognition software, digital signal processing or a combination thereof. Once the positions and/or shapes of the code in the covert code means have been detected and acquired, the acquired data may either be processed in a handset and then transmitted to a local server means, or some processing may be devolved to a central server means.

The article tracked by the system may be an article, or additionally a batch of articles, progressing through manufacture to a point of sale.

As a result of the present invention, a secure labelling and tracking system is provided for particular use against counterfeiting of goods. The invention can be used to authenticate goods in a wide variety of industries such as the textile industry for designer garments, the pharmaceutical industry for drugs, the music and film industry for CDs, videos and DVDs, the computer industry for both software media and hardware, and the banking and finance industry for banknotes and tickets. Another possible use for the system of the present invention is by customs and excise officials for monitoring sales of tobacco and alcohol, to ensure that articles bound for overseas markets are not subsequently resold in the country of origin, such as the UK.

A further use of the system of the present invention is in the field of prevention of retail theft, since the life cycle of a product from manufacture to point of sale can be monitored.

The following examples are given for a better understanding of the present invention and to show more clearly how it may be carried into effect, reference being made to the accompanying drawings in which:

Figure 1 is a schematic representation of an embodiment of a system for tracking an article, according to the present invention; and

Figure 2 is a plan view of part of an article provided with an embodiment of code means for use in the system of Figure 1.

Example 1

An inkjet printing ink is prepared containing a photo- chromic fulgide which absorbs sufficiently in a selected wavelength region of the spectrum when activated by exposure to light from a UV source 2, to be detected and interrogated and read by an adapted bar code reader 4. As shown in Figure 2, a garment 6, such as of cotton, is printed, using this ink, with a unique covert code 8 in the form of a bar code which is invisible to the naked eye and which serves to identify the garment 6 or other product. The location of the covert code 8 is indicated using markers 10. A central database 12 is programmed with details of the garment 6, such as the type of fabric, colour, size, manufacturer, origin and location. The UV source 2 may be a photographic flashgun and may be incorporated into, or separate from, the reader 4. For verification and updating of records, the garment 6 is subjected to illumination from the flashgun 2, in the region of the markers 10, to activate the fulgide material forming the bar code 8 and expose the bar code 8 in an appropriately coloured form for detecting and reading by the reader 4. The reader 4 operates at a detection wavelength appropriate for distinguishing the coloured form of the bar code 8. Appropriate filters are fitted to the flashgun 2, such that, on activation, only ultra-violet light passes through and such that, for deactivation of the fulgide material of the bar code 8 to hidden colourless form, light of wavelength 500 to 600 nm is selected. Reading of the bar code 8 is arranged to take place between two flashes of the different wavelengths. The bar code 8 is converted to a number within a handset of the reader 4 and this number is transmitted by way of a lap-top computer 14 or other suitable apparatus to the central database 12, by way of a wireless communication link 16 such as a radio or WiFi link. Such transmission may be through a central computer 18, such as a personal computer, in a warehouse and also by way of an Internet link 20 or modem telephone link. The central database 12 checks its records and sends back details of the garment 6 required by a person seeking verification. The garment 6 may be tracked from when the covert bar code 8 was applied thereto, and through one or more warehouses, to a retail outlet and finally to a customer. If the customer then returns the garment 6, the database 12 can recall the date of sale, the retail outlet and the price paid, and then reinstate the garment 6 on the database ready for resale.

A Global Positioning System (GPS) technique may be applied to track the location of the garment 6.

Example 2

A fluorescent material, such as coumarin dye, is provided as an active component in a covert code printed in the form of a bar code or data matrix onto a non-fluorescent background on an article such as a concert ticket. As in the previous example, the location of the covert code is indicated by appropriate markers. The region of the covert code is illuminated with low intensity ultraviolet light to activate the code to enable it to be read by a reader in the form of a charge coupled device (CCD) camera with associated image capture software. The captured image is decoded and communicated to the central database, which checks its records and sends back required details to a person requiring verification. In this embodiment, details of a rightful owner of a ticket can be held in the central database and verified at a point of presentation of the ticket, thereby providing a means for preventing redistribution of corporate tickets by way of unauthorised outlets . Example 3

A covert bar code is printed, in the form of a photo- chromic pyran material, orthogonal to and underneath an existing bar code of customary form. The covert code is suitably printed, using inkjet technology, onto a label which also carries the customary bar code, and which is securely attached to an article such as a lap-top computer. All details relating to the article in question are loaded onto the central database. For verification and updating of records, the label is scanned using an adapted bar code reader. The reader incorporates a photographic flashgun for activation of the pyran bar code and is adapted to have a detection wavelength appropriate for distinguishing the coloured form which results from activation. Appropriate filters are fitted to the flashgun such that, on activation, only ultra-violet light passes through. Reading of the code takes place immediately after the flash of light. The detected bar code is converted to a number within a handset of the reader and, as previously described, the number is transmitted to the central database by way of a wireless link.

Example 4

In this example, a conducting polymer material is printed, together with associated electrodes and an electrolyte, in the form of a covert bar code onto a DVD, suitably using inkjet technology. On printing of the bar code, all necessary details regarding the DVD, such as film title, languages, manufacturing site and current location, are loaded onto the central database. The covert bar code is read using a capacitive array detector and after suitable decoding, the read data is transmitted to the central database which checks its records and sends back required details to a person requesting verification.

Example 5

In this example, an electro-luminescent compound, such as poly (p-phenylene vinylene) is printed as a covert code onto a cigarette packet, using inkjet technology. On printing of the code, details, such as the cigarette manufacturer, destination for sale, and quantity, are loaded onto the central database. For verification and updating of records, a voltage is applied to activate the electro-luminescent material of the code whereby it emits light of a certain wavelength for detection. A resulting image is captured using a charge coupled device (CCD) camera equipped with image recognition software. The captured image is decoded and transmitted to the central database which checks its records and sends back required details to a person requesting verification.

Example 6

A photo-chromic thread is prepared containing a spironaphthoxazine material which absorbs sufficiently in the 550 to 650 nm wavelength region of the spectrum when activated to an excited state, and rapidly returns to an unexcited state following deactivation. A pattern of the thread is stitched onto a cloth label for inclusion on a pair of denim jeans, such as on an external pocket thereof. Once the pattern is applied, the central database is programmed with details of the garment. For verification and updating of records, the garment is scanned using an adapted bar code reader. The reader has a photographic flashgun incorporated therewith and has a detection wavelength appropriate for distinguishing a coloured form of the coded pattern of thread upon activation. Appropriate filters are fitted to the flashgun such that, on activation, only ultra-violet light passes through. Reading of the coded pattern takes place immediately after a flash of light. A resulting captured image is decoded and transmitted to the central database, which checks its records and sends back details requested by a person requiring verification of the particular garment.

Example 7

Two electro-chromic inks are prepared, one containing Prussian blue and the other containing PEDOT (poly (3,4- ethylenedioxythiophene) ) . An image is printed onto a lower electrode using the Prussian blue ink and a different image is printed onto an upper electrode using the PEDOT ink. The electrodes are assembled to form a cell, with a membrane of Nafion perfluorosulphonate ionomer material between them to facilitate electron mobility. The Prussian blue image is continually visible unless a voltage is applied to the electrodes of the cell. Upon application of a voltage, the Prussian blue ink becomes oxidised from a dark blue colour to a pale yellow colour and the PEDOT ink becomes reduced from a pale blue colour to a dark blue colour. As a result, a change takes place in an initial image formed by the overlying materials in the cell, and this change is detected. A handset for scanning the arrangement comprises a means for applying a voltage to the cell and a charge coupled device (CCD) camera for image capture. Decoding of the captured images is effected in the handset. Decoded images before and after voltage application are transmitted to the central database, verification only being provided by the central database if both decoded images are correctly transmitted to the central database.

Referring again to Figure 1, a radio camera 22 (which may incorporate a sensor and/or a data display) and/or a web camera 24 may be included in the system to provide improved portability.

Example 8

An electrochromic material which is normally colourless is printed onto an anode which is fixed to an article, and a barcode is printed on top of the colourless material as an electrochromic material which is normally coloured, and can be read using a conventional barcode reader. Interposed between the two layers is a layer of transparent solid polymer electrolyte. A further code is printed on top of these layers, in a transparent solid polymer electrolyte material.

In this way, a barcode which is not covert can be changed from one value to another in a covert manner by selectively changing the colour of the substrate upon which it is printed in one or more predetermined regions so as to add to or subtract from the non-covert barcode depending upon whether the normal state of the electrochromic material is coloured or colourless.

A reader incorporates a cathode such that, when the cathode is applied to the covert code, contact is made through the electrolyte and the electrochromic materials are switched from coloured to colourless or vice versa, such that a code different to that normally visible is revealed. The revealed covert code may be read using, for example, a CCD camera.

Example 9

A covert code is printed as a spiroindolinonaphthoxazine compound on a substrate. The covert code is activated by a UV source within a reading device, the covert code being readable immediately after activation and for a predetermined time thereafter. The contrast ratio between the foreground (as represented by the code) and the background as represented by the substrate on which the code is printed is measured by the reading device immediately after activation and after the predetermined time, in each case along with the ambient temperature. The contrast ratios and ambient temperatures are transmitted to a server together with the code and the resulting database therefore contains data relating not only to the code, but also relating to the response of the substance for printing the code.

During subsequent reading of the code, the response is compared with the information contained in the database to verify the substance used to print the code as well as the authenticity of the code itself.

According to embodiments of the present invention, all communications between the system server and clients requiring verification details of articles may be arranged to be secure, using encryption algorithms implemented in Java software or similar. A Secure Socket Layer (SSL) or Transport Layer Security (TLS) socket is opened on the server, and a client is authorised to access this socket if certificates held by the client and by the server are coherent. Digital certificates are issued by a trusted third party and distributed to the server and the client. An automatic server authentication and an optional client authentication are performed before any communication begins .

Every communication between server and client is encrypted using DHE (Diffie Hellman Encryption) or RSA 25 (Rivest, Shamir, Adleman) or ECC (Elliptic Curve Cryptography) for example. These public key algorithms are extremely difficult to break and are completed with standard public key algorithms, such as DES (Digital Encryption Standard) , triple DES and RC4 (Rivest Code) . The public key encryption encrypts a message with the public key of the person it is destined to. The recipient decrypts the message with his or her own private key.

To ensure that a message has not been tampered with, a hash code is calculated and attached to the message. The recipient also calculates the hash code and compares it with the original code. The message is authenticated if both hash codes produce the same result. The algorithms used to calculate those hash codes may be, for example, SHA (Secure Hash Algorithm) or MD5 (Message Digest) .

This message encryption ensures that the correct data is transmitted securely over a public network without risk of anyone reading or changing the transmitted message. A secure connection between the code reader and the central database is now guaranteed.

The transmitted message is the encoded version of the covert code represented by a label on an article. This code is a randomly generated number. There are different ways available for generating random numbers based on physical effects such as scattered beads, oil on water, and mixing of coloured paints, and which give rise to effectively random numbers. It Should be noted such true random patterns are to be distinguished from pseudo- random numbers such as those generated by digital computer algorithms, for example. The main advantage of the random number is that it is easy to read and easy to produce. For transmission purposes this code can either be encrypted or left as a random number before reaching the central server of the system.

A unique random number is assigned to each article so that every article is associated with a single number. Because the number is entirely random, sequentially assigned codes will bear no relation to each other, that is the code means is non-sequential and unpredictable. The number is then associated in the database with a description of the article. This association of the article with a unique number allows a user of the system to individually track every article and possibly update certain features of the description of the article held in the database as the code means is scanned and sent to the remote central database.

The secure database holds all the information pertaining to each article. That is, no information specific to the article forms any part of the code means. Each article has a unique code means arbitrarily assigned such that as articles progress from the early stages of manufacture right through to a point of sale, each article is traceable. The database contains information such as point of origin, colour, size, status and current location and upon receipt of the code means the relevant information for that article is sent back to the person requiring verification. Consequently, the information regarding the article is further secured because a pathway for a codebreak into the encryption of the number is not provided, making very difficult the determination of the assigned random number and hence access to the correct record (s) from the database even if unauthorised access has been gained to the database. Thus, where during transmission the code means is random and encrypted, unless the encryption key is compromised it will not allow the random code means to be recovered.

In the event a transmission from the database is compromised, that is if an eavesdropper should decipher the transmission and recover information specific to the article, the information will be of use only for this one interaction; the eavesdropper will not gain anything by relating the random number to the information relating to the article. To improve security further, it is possible not to transmit information from the database beyond an indication whether the article is authentic or not.

Following verification, the records in the database are amended to update the location, status and ownership of the article. The location of the articles can be verified in real time by way of Global Positioning System (GPS) technology. Certain features of the information on the database are write-protected, such as the article description, including details of the manufacturer, colour, size and place of origin.

Claims

1. A system for tracking an article (6), such as for determining authenticity thereof, the system being characterised by:

a unique random code means (8) on or associated with the article;

means (4) adapted to detect the unique random code means;

a remote database (12) adapted to store information relating to the article corresponding to the unique random code means; and

means (16, 22) adapted to transmit data between the detecting means and the database.

2. A system as claimed in claim 1, characterised in that the database (12) comprises a secure database.

3. A system as claimed in claim 1 or 2, characterised in that the transmitting means (16, 22) is adapted for two-way transmission between the detecting means (4) and the database (12) .

4. A system as claimed in any preceding claim, characterised in that the code means (8) is selected from a one dimension or two dimension bar code or radio frequency identification tag.

5. A system as claimed in any preceding claim, characterised in that the code means (8) is encrypted.

6. A system as claimed in any preceding claim, characterised in that global positioning system means is provided to determine the location of the article (6) each time the code means (8) is detected by the detecting means (4), location data relating to the article corresponding to the code means being stored in the database (12) .

7. A system as claimed in any preceding claim, characterised in that the code means (8) is covert.

8. A system as claimed in claim 7, characterised in that a luminescent code means (8) is applied to non- luminescent background.

9. A system as claimed in claim 7, characterised in that a non-luminescent code means (8) is applied to a luminescent background.

10. A system as claimed in claim 7, 8 or 9 and including a fiducial mark (10) to indicate the location of the covert code means (8) .

11. A system as claimed in any one of claim 7 to 10, characterised in that the detecting means (4) comprises means (2) for activating the covert code means (8) to enable interrogation thereof, and means (4) for interrogating the activated code means.

12. A system as claimed in claim 11, characterised in that the covert code means (8) is invisible to the naked eye and is adapted to be activated by response to application of an external stimulus by the activating means (2 ) .

13. A system as claimed in any one of claims 7 to 12, characterised in that the covert code means (8) is selected from a photo-responsive material, a thermo- responsive material, an electro-responsive material, and a material with specific optical, dielectric or conductive properties, and a combination thereof.

14. A system as claimed in claim 13, characterised in that the photo-responsive material is selected from a photo-chromic material and a photo-luminescent material.

15. A system as claimed in claim 14, characterised in that the photo-chromic material comprises a material selected from bianthrones, fulgides, spiropyrans, spirooxazines, pyrans, oxazines, naphthopyrans, spironaphthoxazines, diarylethenes, and mixtures thereof.

16. A system as claimed in claim 15, characterised in that the activating means (2) comprises an ultra-violet light source and the detecting means (4) comprises an optical detecting means.

17. A system as claimed in claim 15 or 16, characterised in that the photo-chromic material is selected from photo-reversible and thermally reversible materials.

18. A system as claimed in claim 17, characterised in that the colour of the photo-reversible material is removed using a second application of light.

19. A system as claimed in claim 17, characterised by monitoring a rate of fade of colour of a thermally reversible material after activation.

20. A system as claimed in claim 19, characterised by a temperature sensor for compensating for temperature dependence of the rate of decolouration.

21. A system as claimed in claim 14, characterised in that the photo-luminescent material comprises luminescent molecules selected from anthracenes, fluoresceins, rhodamines, coumarins and indocyanine green.

22. A system as claimed in claim 21, characterised in that the activating means (2) comprises a filtered light source such that the luminescent molecule in the material absorbs at a wavelength of irradiation of the filtered light from the source.

23. A system as claimed in claim 13, characterised in that the thermo-responsive material comprises a thermo- chromic material which is activated to produce a change in colour thereof by application of heat.

24. A system as claimed in claim 23, characterised in that the thermo-chromic material is selected from a copper or silver salt of mercuric iodide, doped or undoped vanadium dioxide, 2, 5-dinitrosalycylic acid, and a liquid crystalline material.

25. A system as claimed in claim 13, characterised in that the electro-responsive material is selected from an electro-luminescent material, an electro-chromic material and an electrically conducting polymer material.

26. A system as claimed in claim 25, characterised in that the electro-luminescent material is selected from a derivative poly (p-phenylene vinylene) , polythiophene and a polymer doped with a luminescent material.

27. A system as claimed in claim 25 or 26, characterised in that the electro-luminescent material is sandwiched between an anode and a cathode means .

28. A system as claimed in claim 27, characterised in that at least one of the anode and cathode means is made of an optically-transparent thin conducting film.

29. A system as claimed in claim 13, characterised in that the electro-chromic material is selected from viologens, metal hexacyanoferrates, metallopolymers, mettalocyanines and polymers which change colour on application of an electrical potential.

30. A system as claimed in claim 29, characterised in that the electro-chromic material is provided as a patterned layer on at least one of an anode means and a cathode means .

31. A system as claimed in claim 30, characterised in that the anode and cathode means are separated by an ion- conducting electrolyte with negligible electronic conductivity.

32. A system as claimed in claim 29, 30 or 31, characterised in that the electro-chromic polymer material is selected from poly (pyrrole) , poly (aniline) , poly (thiophene) , poly (acetylene) , poly (isothionaphthene) and poly (p-phenylene) .

33. A system as claimed in any one of claims 7 to 32, characterised in that means is provided additionally to detect the spectral and/or temporal characteristics of at least part of the covert code means for comparison with corresponding information stored in the remote database relating to the article.